Method of making elastic thread and reticulated sheets of rubber or similar material



'F eb. 1936. M, HARRISON, 2,030,208

METHOD OF MAKING ELASTIC THREAD AND-RETICULATED SHEETS OF RUBBER 0RSIMILARMATERIAL Filed Oct. 20, 1932 2 Sheets-Sheet l mmaum illlllll IIIIII o CIFLICICKIICICEJ ion/1 795521 5027 Feb. 11, 1936.

M. M. HARRISON METHOD OF MAKING ELASTIC THREAD AND 'RETICULATED SHEETS 0RUBBER OR SIMILAR MATERIAL Filed Oct. 20, 1932 trail-MI r 2 Sheets-Sheet2 Patented Feb. T 1, 1936 PATENT OFFICE METHOD OF MAKING ELASTIC THREADY AND RETICULATED SHEETS OF RUBBER v I OH SIIWILAR MATERIAL ApplicationOctober 20, 1932, Serial No. 638,772

Claims.

This invention relates to a method of makin elastic thread andreticulated sheets of rubber or similar material and articles producedthereby and is especially useful in the production of such materials tobe used in the manufacture of elastic fabrics.

The principal objects of the invention are to provide a method by whicha' product may be produced with a minimum expenditure of labor andwithout waste material, and to provide a new and useful product ofuniform quality.

Other objects of the invention will appear from the followingdescription and the accompanying drawings illustrating the method.

In the drawings:

Fig. 1 is a diagrammatic view showing in elevation and partly in sectionapparatus which may be used in practicing the method of the invention inthe manufacture of elastic thread or sheet material.

Fig. 2 is a section on line 22 of Fig. 1 showing the support-breakingdevice.

Fig. 3 is a diagrammatic view showing in elevation and partly in sectionapparatus which may be used in practicing the method of the invention inthe manufacture of reticulated Fig. 6 is a perspective view of a pieceofv reticulated elastic sheet material or fabric, parts being brokenaway and in section to show the constructlon thereof.

7 isaplanview of aiperforated' sheet: of material .having a coating ofelastic material deposited thereon.

Fig. 8 is a section on line 8-8 of Fig. '7. Briefly stated, theinvention consists in depositing a solution or dispersion of rubber orsimilar elastic material upon a' filament or netted web of materialconstituting a temporary support, vulcanizing or otherwise chemicallychanging the deposit to provide an elastic coating on the support, andprogressively or otherwise disintegrating the support to provide anelastic and extensible structure.

Referring to the drawings, the invention may be practiced by drawing oneor more filaments or cords l0, l0, of weak materlalsuch as looselytwisted short cotton fibers or of untwisted cellulose or other materialthrough a bath ll of a solution adapted to coagulate the material to bedeposited thereon whereby the filaments or cords are impregnated orcoated with the coagulant solution. The filaments or.cords are thenpassed through a solution or natural or artificial dispersion of rubberor similar material l2, whereupon the coagulant carried by the filamentor cord will cause the coagulation of a film of the solution ordispersion upon the surface of the filament or cord. A suflicientlythick film may be obtained by repeated dipping and drying without thecoagulant if desired, but when a coagulant solution such as zincchloride is used, the coagulant may also act to disintegrate orsubstantially Weaken the supporting cord or filament.

. Where it is desired to deposit rubber or a similar material from asolution of the same in organic solvents the coagulant may be dispensedwith and the filaments or cords I0, I 0', passed directly through thebath l2 of rubber or similar solution in which case a thinner depositwill ordinarily result.

The bath l2 may be contained in a tank 13 through the bottom of whichthe filaments or cords l0, l0, may enter through a flexible selfclosingguide l4 formed of soft vulcanized rubber.

After receiving a deposit of the required thickness, which may sometimesnecessitate the application of more than one coat of deposited material,the filaments or cords are drawn through a drying chamber l5 throughwhich heated air or other gases may be circulated to facilitate drying.The filaments or cords arethen subjected to vulcanization, preferably bybeing passed through a chamber l6 heated by steam coils l1.

After vulcanization the supporting filaments or cords when notcompletely disintegrated, may bedlsintegrated by being broken intodiscontinueous sections I8 within the elastic coating I9 to provide anelastic extensible thread or cord. A convenient apparatus for thispurpose comprises a pair of platens20, 2|, located along the path of thecords and provided with spaced ribs 22, 23 on their opposed facesarranged to traverse the path of the cords. The platen 2| isstationarily mounted so that its ribs 23 contact with or barely clearthe coated cords passing thereover and the platen 20, whose ribs.22 arein intercalated relation to the ribs 23, is mounted for verticalmovement. Platen is provided with means for intermittently. raising andlowering it to such an extent as to force its ribs 22 into the spacesbe- "tween ribs 23, as indicated by the dot and dash lines, therebystretching the cords beyond their elastic limits, whereupon the cordsare broken into short lengths whereas the elastic coatings are unbroken.For this purpose the platen 20 and an armature 25 extending above theplaten through a solenoid 26 may be used to project the plate againstthe cordsat timed intervals by intermittent energizing of the solenoid.

The elastic cords having their fibrous or filamentous supports brokenare then wound upon a reel 21. By close spacing of the cords ID acontinuous sheet may be produced if desired.

In applying the method to the production of reticulated or perforatedsheets of elastic material a weak net fabric 30 or a perforated web ofpaper 42 is provided in place of the filaments or cords and is coated ina similar manner as shown in Fig. 3 by being passed from a roll 3|through a coagulant bath 32, a bath 33 of rubber latex or other solutionor dispersion of rubber or similar elastic material, and then through adrying chamber 34 and vulcanizing chamber 35.

The reticulated or perforated sheet of material is then passedsuccessively through devices 36 and 31 adapted to break the support. Forthis 'purpose a device 35 similar to that previously described forbreaking cord supports may be used for breaking the longitudinal or warpcord members of the support and a similar device 31, but

having its platens arranged with their cordbreaking ribs across the weftthreads of the support, may be used for breaking the lateral elements orweft threads. When net fabric is used as the support the resultingreticulated sheet comprising a support having its warp and weft elementsbroken to provide discontinuous portions, 38 and 39, all enclosed in acontinuous elastic covering 40 of reticulated form, is then wound on areel 4|. The reticulated or perforated sheet will be extensible andelastic in all directions and may be used for manufacturing elasticbandages, girdles and the like where both elasticity and porosity tofacilitate ventilation are necessary or desirable.

7 Where perforated paper is used as the suppo the rubber coating 40 willextend over the faces of the sheet and through the apertures leavingsmaller apertures in the resulting sheet of material than there were inthe original sheet of paper. When such a sheet is stretched the papersupport, which is entirely enclosed in rubber, will be broken or torninto small disconnected portions thereby providing a perforate elasticsheet of material.

I claim:

1. The method of making an elastic structure which comprises providing asubstantially nonextensible support of substantially the same extent asthat of the elastic structure to be produced, forming a coating ofelastic material around the support, and so disintegrating the supportas substantially to destroy its effectiveness as a tension element.

2. The method of making an elastic structure which comprises providing asubstantially nonextensible cord with a coating of elastic material,and. disintegrating the cord by tension intermittently applied tosuccessive portions of the finished article.

3. The method of making an elastic cord which comprises roviding asubstantially non-extenmay be supported by contractile coil springs 24sible cord with an enclosing coating of elastic material and treatingthe resulting article to substantially destroy the effectiveness of thecord 'as a tension member.

4. The method of making a reticulated sheet of elastic material whichcomprises providing a reticulated support of substantiallynon-extensible warp and weft members, coating each warp and weft memberwith a continuous elastic coating without filling the interstices of thesupport, and so disintegrating the support as to substantially destroyits eifectiveness as a tension member.

Y 5. The method of making a reticulated sheet of elastic material whichcomprises providing a reticulated support of substantiallynon-extensible warp and weft members, treating the support with asubstance adapted to coagulate a coating material, depositing an elasticcoating thereon, and disintegrating the support by tension applied in aplurality of directions.

6. The method of making a reticulated sheet of elastic material whichcomprises providing a reticulated support of substantiallynon-extensible material, treating the support with a substance adaptedto weaken the support and coagulate a coating, applying a coating of anelastic substance to the support and completing disintegration of thesupport by tension applied to the resulting sheet of material in aplurality of directions.

7. The method of making a reticulated sheet of elastic material whichcomprises providing a reticulated support of substantiallynon-extensible sheet material, treating the support with a substanceadapted to eventually disintegrate the support and to coagulate acoating applied thereto, and depositing a coating of elastic materialabout each member of the support without filling the coat of elasticmaterial, disintegrating the warp I members of the support by tensionapplied longitudinally of the sheet, and disintegrating the weft membersby tension applied cross-wise of the sheet.

10. The method of making an extensible struc;

ture which comprises providing a tension-resisting support having arelatively low extensibility and having substantially the same extent asthat of the extensible structure to be produced, forming a coating ofhighly extensible material upon the support, and then substantiallydestroying the eifectiveness of the support as a tension-resistingelement.

MARION M. HARRISON.

